The method json does only exist in Illuminate\Contracts\Routing\ResponseFactory, but not in Illuminate\Http\Response.

It seems like the method you are trying to call exists only in some of the
possible types.

Let’s take a look at an example:

classA{publicfunctionfoo(){}}classBextendsA{publicfunctionbar(){}}/** * @param A|B $x */functionsomeFunction($x){$x->foo();// This call is fine as the method exists in A and B.$x->bar();// This method only exists in B and might cause an error.}